Winging it for science: study of disease-free bat could help humans

By
Bridie Smith

BATS’ ability to fly could provide vital genetic clues to prevent and treat fatal diseases in humans, according to researchers.

Winging it for science: study of disease-free bat could help humans

Secret to longevity ... David's myotis, the tiny microbat native to China, was one of two bat species selected by researchers for a study that links genetic changes with the evolution of flight. Photo: CSIRO

BATS' ability to fly could provide vital genetic clues to prevent and treat fatal diseases in humans, according to researchers.

The only mammal capable of sustained flight, bats are notorious for harbouring some of the deadliest diseases known to humans, including Ebola, rabies and SARS. However the animals do not die from the diseases – let alone get sick.

In the first comprehensive interpretation of the bat genome, researchers from CSIRO's Australian Animal Health Laboratory in Geelong and the Beijing Genome Institute set out to establish why.

They started by mapping the genome of two distantly related bat species, the Australian black flying fox and the Chinese microbat David's Myotis. The results were compared with the genome of eight other mammals, including humans which have a genome roughly double the size of a bat's about four million letters.

''We found that the bat immune system has evolved to resist the damage free-radicals cause to DNA,'' said CSIRO post-doctoral fellow Chris Cowled.

This is linked to flight which as an energy intensive activity, produces toxic free-radicals. Free-radicals are a metabolic bi-product known to contribute not only to diseases such as cancer but also to ageing.

This is notable as bats are also renowned for their longevity – living about three-times longer than their body size would suggest. Microbats, which can weigh as little as five grams, can live in excess of forty years.

Dr Cowled said this again suggested bats have an ability to slow the ageing process by minimising the damaging effects of free-radicals on their DNA.

Among the genes found after sequencing the genome of two bat species, was the P53 gene: a gene found in humans which is implicated in cancer. However, in bats it appears to play a role in the immune system as well.

''We're proposing that the evolution of flight led to a sort of spill over effect, influencing not only the immune system, but also things like ageing and cancer,” Dr Cowled said.

He said an improved genetic understanding of the animal, which has been around since the time of dinosaurs, could lead to more targeted research and treatment of human diseases.

''If we can understand how the bats are resisting tumours, and how they are handling highly virulent viruses without showing any sign of disease and how they are living for a long time despite having a high level of free-radicals, that will enable us to design new treatments,'' he said. ''Maybe we will learn which genes to target in human disease.''